It is known to produce metal beverage containers having a screw-on closure cap. An open end of the container may be opened and resealed using the screw-on closure cap. A number of references teach such screw-on closure caps with many different features and differing levels of success.
One method involves production of can body having a necked-in upper portion terminating at a threaded open end. These containers generally resemble screw top bottles. The threads are typically mechanically formed using the excess metal at the open end of the can body. Formation of the threads, however, is a difficult manufacturing process.
To ease this difficulty, a method of providing a threaded container has been introduced which includes providing an annular outsert at the open end of the container. The outsert is produced from a polymeric material or the like and includes threads on an outer surface. The threaded outer surface cooperates with a threaded surface on a closure cap to seal the cap to the container. The outserts, however, have a tendency to slip vertically or rotate about the container. Because of this, many solutions have been introduced to prevent outserts from unwanted movement on a container body, none of which achieving great success.
Recently, lug-type resealable closure systems have been introduced into the beverage market. Such closures are described in U.S. Pat. No. 6,082,944, issued to Bachman et al. These closure systems a set of elongated lugs located about the container, at an upper neck portion. These lugs cooperate with a second set of inwardly extending lug members formed in a curled rim of a cap member. When the cap member is attached to the upper neck portion, the cooperating lug members draw the cap against a curled seal rim, of the container. These closure systems overcome some of the drawbacks of the threaded closures because it avoids the necessity for the relatively expensive operation of threading the wall of the container body and also enables the use of a container which has a very short skirt and therefore requires less material then the relatively long-skirted caps usually employed as a screw closure. However, the lugs are still difficult to form. Therefore, a lug-type closure system that can be reliably manufactured while overcoming the problems associated with fully threaded closures and providing a resealable closure cap is needed.
The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior containers of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.